Bug #7391098
The existing code was doing a make current to guarantee we have a
current context. This can however fail when the surface is destroyed
which could lead to GL calls without an EGL context, and therefore
potential leaks. This change fixes the issue by using a technique
found in HardwareRenderer.destroyHardwareResources(). If the surface
is not available then we use a special 1x1 pbuffer as a way to get
a valid context.
Change-Id: I716d3799bf90120d793d76e90a83956837ecd491
bd17bd3431